Introduction: Total knee arthroplasty is associated with moderate to severe pain, and effective analgesia is essential to facilitate postoperative recovery. This retrospective cohort study examined the analgesic and rehabilitation outcomes associated with 48-hour continuous femoral nerve block, local infiltration analgesia, or local infiltration analgesia plus adductor canal nerve block.
Methods: Patients undergoing total knee arthroplasty under spinal anesthesia, during an 8-month period, were retrospectively assessed with a targeted review of 100 patients per group. Records of eligible patients were reviewed to identify the analgesic technique used and the primary outcome of distance walked on postoperative day 1. Secondary outcomes included ambulation on days 2 and 3, numeric rating scale pain scores, opioid consumption, and adverse effects and discharge disposition.
Results: Two hundred ninety-eight eligible patients were reviewed. Local infiltration analgesia and local infiltration plus adductor canal block were associated with longer distances walked on postoperative day 1 than continuous femoral nerve block (median values of 20, 30, and 0 m, respectively; P < 0.0001). The addition of adductor canal block was associated with further improvement in early ambulation benchmarks and a higher rate of home discharge compared with only local infiltration (88.2% vs 73.2%, P = 0.018). Local infiltration with or without adductor canal block was associated with lower pain scores at rest and during movement for the first 24 hours and lower opioid consumption than continuous femoral nerve infusion.
Conclusions: Local infiltration analgesia was associated with improved early analgesia and ambulation. The addition of adductor canal nerve block was associated with further improvements in early ambulation and a higher incidence of home discharge.